Date of Graduation
Statler College of Engineering and Mineral Resources
Mechanical and Aerospace Engineering
Darran R Cairns
Hydrophobic coatings are useful for a wide range of applications including anti-fouling, anti-corrosive, and anti-icing. There are also a number of emerging applications in which transparency is critical such as optoelectronics, touchscreens, and smart windows. For many of these applications, resistance to abrasive wear is also important. Typical low-surface energy coatings such as polytetrafluoroethylene (PTFE) have poor mechanical strength which leaves them susceptible to abrasive wear. To combat this problem, functional moieties can be encapsulated using a sol-gel method to provide improved substrate adhesion and hardness while maintaining transparency and functionality. While this provides an improvement for many applications, the inherent porosity from this approach has a detrimental effect on the overall performance of the coating. A solution to this is to provide a nanoparticle-reinforced sol-gel matrix to improve the hardness and abrasive wear resistance. These coatings can improve the lifetime and performance of the aforementioned applications by protecting them from the harsh environments typically encountered.;Silica nanoparticle-reinforced fluorinated silica coatings were deposited by sol-gel synthesis on glass substrates via dip coating. Varying amounts of colloidal silica nanoparticles from 0.5 to 10 weight percent of precursor were added. Structural, mechanical, surface, functional, and tribological properties were examined to elucidate the effects of the nanoparticles on the silica matrix. A lab-built reciprocating abrasive wear apparatus, a reciprocating tribometer, contact angle goniometry, nanoindentation, nano-scratch, atomic force microscopy, and stylus profilometry were used to investigate these properties. Experimental results show that the particle-reinforced coatings provide increased overall indentation hardness as well as a decreased wear rate while maintaining comparable functional sustainability to coatings without the added silica particles.
Banerjee, Derrick A., "Sol-Gel Derived Wear-Resistant, Hydrophobic, Particle-Reinforced Silica Coatings" (2012). Graduate Theses, Dissertations, and Problem Reports. 4829.